A shifting device for an automatic transmission of a vehicle is known from the document DE 101 25 700 A1 having a pulse counter by means of which the sequential pulses of a manual command by a driver are functionally linked together. A shifting signal can be generated depending on the linkage, whereby a driver's wish can be satisfied even after several downshifts or upshifts. For this purpose, a selector lever can be manually shifted by the driver in the direction of an upshift. When the selector lever reaches a “plus” shifting position, a plus sensor is activated, and a corresponding signal is sent to the pulse counter of an electronic control unit. When the selector lever contrastingly reaches a “minus” shifting position, a minus sensor sends a corresponding signal for a downshift request.
Unfortunately, a driver of a vehicle equipped with a shifting device for setting a desired drive engine speed level is forced, depending on each existing operating state of the vehicle or the vehicle drivetrain thereof, to actuate the selector lever several times sequentially to engage the required transmission ratio in a transmission device of the vehicle drivetrain.
A method for controlling an automatic transmission in which a downshifting function is initiated upon actuating a brake pedal is disclosed in DE 197 55 076 C1. During the method while initiating the function, an electronic transmission control calculates a new downshifting point while the throttle valve is closed by adding a characteristic value to a basic downshifting point. Consequently, when the vehicle brake is actuated, downshifting occurs at vehicle speeds higher than is the case when the vehicle brake is not actuated in order to more strongly exploit the braking effect of a drive engine of a vehicle drivetrain during vehicle deceleration.
Unfortunately, the driver is not supported in the known method when he wants the vehicle drivetrain to change to a desired operating status during manual touch mode by means of which the driver is provided with a greater amount of tractive force.
A method for operating a transmission device with a plurality of transmission ratios is described in the document DE 10 2010 030 495.6 by the applicant. A transmission ratio of the transmission device is automatically selected in automatic shifting mode depending on a current driving state of a vehicle. During a manual shifting mode, a transmission ratio is selected depending on a driver's specified wish. When a driver's shifting request exists, automatic shifting mode changes to manual shifting mode. Each transmission ratio is assigned a transmission-ratio-specific threshold value of the transmission output speed or an equivalent speed value. Given a driver's downshift request, a target transmission ratio to be engaged by the transmission device is determined depending on the current transmission output speed or an equivalent speed value. The transmission ratio selected as a target transmission ratio has a transmission-ratio-specific threshold value that is greater or equal to the current transmission output speed or an equivalent speed value.
When switching from automatic shifting mode to manual shifting mode, due to the proposed procedure in certain circumstances multiple shifting is activated that yields significant spontaneity. Subsequently however in manual shifting mode, only single shifting is activated in each case when a driver's request element is actuated which does not yield spontaneity acceptable to the driver.
In another procedure known from practice by means of which a driver's requested operating state for a vehicle drivetrain can be set with at least approximately acceptable spontaneity, particularly in the region of a transmission device, cyclical additional upshifts or downshifts are requested after the expiration of a delay when a driver continuously actuates a manual request element.
Unfortunately, this procedure is performed independent of the current operating state of the vehicle which is why the desired spontaneity is available during the procedure and not over the entire operating range of a vehicle.